Feature:1. PROFESSIONAL DESIGN: 30.5mm flywheel connector adapter and 22T single speed flywheel design, suitable for a wide range of popular electric bikes.2. METAL MATERIAL: Bike freewheel adapter set is made of premium iron material, oil resistance, long service life, reliable and durable performance.3. FINE CRAFTSMANSHIP: With its exquisite craftsmanship, the flywheel is durable and won't be deformed over time, keeping its function and performance.4. SIMPLE INSTALLATION: The flywheel with connector is easy to install, convenient for professional bike mechanics and DIY enthusiasts.5. STABLE AND EFFICIENT: Provides stable and efficient power transmission. Fine engineered design reduces friction and maximizes energy transfer for seamless operation of your machine.Specification:Item Type: Bike Freewheel Adapter SetMaterial: Iron.Package List:1 x Connecting Head 1 x Flywheel